Cygwin is a great alternative for those who feel constrained by working with the Windows environment. Cygwin lets you employ the best parts of each environment to fit your needs, whether through porting and development of applications, or simply using the applications in this flexible, powerful system.

Cygwin works well in general, but speed is an issue for me. My shell scripts are slow on Cygwin compaired to linux on the same hardware. Applications that I compile with cygwin are much slower then if I just compile them to native windows binary.

I love cygwin, but anyone saying it has no performance issues is either fibbing, or they only play around with the pre compiled tools, or lightweight shell scripts.

The binaries linked to the cygwin environment are native Windows binaries; they're just using a DLL providing a POSIX layer not provided by Windows by default.

Forking under Windows can be expensive. There are other performance considerations one might make, but since your comment is just vague "it's slow" there really isn't much one can tell you. If you use a lot of indirection to accomplish the same goal as without, it will of course be slower.